Console communications are used in server systems to send and receive status, control and configuration information. Console communications are typically transmitted and received via a single LAN interface (i.e., a LAN that combines console and payload communications), or via a cable to an RS-232 port on a server.
When there is no console LAN, each server typically includes an RS-232 port for console communications. If a large number of servers are to be controlled, then a complex, hard-to-manage wiring bundle to each individual server's RS-232 port must be implemented. Using an RS-232 port for console communications is sufficient for a standalone server, but when the server is integrated with many others in a common chassis, a separate cable for each server is difficult to maintain and configure. If any consolidation is to be done, it is typically implemented by a separate device outside of the chassis. Consequently, most customers route all of the cables a short distance to a special switch, such as those made by Raritan and Lantronics. Though this simplifies the cable bundle by giving a single port of access to the congregation of servers, it adds cost to the system in terms of money and space.
If a single LAN interface is used, there is a security hole in that LAN console control information commingles with payload information on a single customer payload LAN. This commingling of signals on a single LAN allows for unauthorized snooping, and the potential for unauthorized communications to the console devices. For a single LAN interface, a security driven software layer can used (at additional cost), but there is a possibility that the security layer could be cracked.
It would be desirable for a server system to provide a single management card for console communications with multiple modules within the server system, rather than using a separate I/O connector for each module. It would also be desirable for the management card to provide a variety of interfaces that can be active at the same time, so that users can work remotely as well as locally at the server system, which would simplify procedures used by field support engineers.